Bisphenol A (BPA) is a high-volume chemical used in plastic production and has raised concerns about its effects on human health and the environment. This review summarizes the effects of low-dose BPA exposure (below 50 mg/kg/day) in laboratory animals, focusing on its endocrine-disrupting properties. BPA exhibits estrogenic activity, but it also acts as a selective estrogen receptor modulator (SERM), sometimes antagonizing estrogenic effects. It can bind to androgen and thyroid hormone receptors, though higher doses are required for these effects compared to estrogenic ones. BPA influences enzyme activity and hormone receptor expression, affecting metabolism, neuroendocrine function, and brain development. Developmental exposure to BPA during gestation through puberty leads to "organizational" effects, which are long-lasting and can alter reproductive systems, brain structure, and behavior. These effects include changes in estrogen receptor expression, neuroendocrine function, and behavioral traits. BPA exposure during critical periods of development can result in persistent alterations in the brain, reproductive system, and metabolism. For example, it can affect the development of the mammary gland, prostate, and testes, and may increase the risk of prostate cancer. BPA also influences immune function, increasing immune responses in offspring. Adult exposure to BPA can lead to "activational" effects, which are reversible and may affect reproductive function, behavior, and metabolism. BPA exposure during adulthood can alter testosterone levels, prostate size, and sperm production. It can also affect the immune system, increasing immune responses. The review emphasizes the importance of using appropriate positive controls in experiments to accurately assess BPA's effects. It also highlights the need for careful experimental design, including the use of appropriate animal models, feed, and housing conditions to minimize confounding factors. The review concludes that BPA exposure at low doses can have significant effects on various physiological systems, and further research is needed to fully understand its impacts.Bisphenol A (BPA) is a high-volume chemical used in plastic production and has raised concerns about its effects on human health and the environment. This review summarizes the effects of low-dose BPA exposure (below 50 mg/kg/day) in laboratory animals, focusing on its endocrine-disrupting properties. BPA exhibits estrogenic activity, but it also acts as a selective estrogen receptor modulator (SERM), sometimes antagonizing estrogenic effects. It can bind to androgen and thyroid hormone receptors, though higher doses are required for these effects compared to estrogenic ones. BPA influences enzyme activity and hormone receptor expression, affecting metabolism, neuroendocrine function, and brain development. Developmental exposure to BPA during gestation through puberty leads to "organizational" effects, which are long-lasting and can alter reproductive systems, brain structure, and behavior. These effects include changes in estrogen receptor expression, neuroendocrine function, and behavioral traits. BPA exposure during critical periods of development can result in persistent alterations in the brain, reproductive system, and metabolism. For example, it can affect the development of the mammary gland, prostate, and testes, and may increase the risk of prostate cancer. BPA also influences immune function, increasing immune responses in offspring. Adult exposure to BPA can lead to "activational" effects, which are reversible and may affect reproductive function, behavior, and metabolism. BPA exposure during adulthood can alter testosterone levels, prostate size, and sperm production. It can also affect the immune system, increasing immune responses. The review emphasizes the importance of using appropriate positive controls in experiments to accurately assess BPA's effects. It also highlights the need for careful experimental design, including the use of appropriate animal models, feed, and housing conditions to minimize confounding factors. The review concludes that BPA exposure at low doses can have significant effects on various physiological systems, and further research is needed to fully understand its impacts.